The recruiting team does a great job. They are very helpful and always willing to assist. On the day of your interview, take full advantage of your recruiters by asking about the company, the background of engineers working there, and what they expect from their potential hires. Although you may know a lot about the company from online sources, I recommend asking the recruiters these questions as you will get a clearer idea.

Focus on a lot of functional test cases first, especially when they ask you to test the code you write. Don't worry about where it is used or which application makes use of this code, as you may waste time clarifying and get lost in thoughts. As the interviewer would say, "I just need functional test cases."

But remember, when they ask you to test an application or something from the real world, then think methodically. Consider: test environment, use cases, functional tests, and special test cases like globalization tests, integration, etc.

Make sure you understand the question. Sometimes they may not give all the details in the question they ask; they want to see how you get the most information out of them. Don't proceed without understanding the question! Also, confirm whether you are allowed to use additional data structures or helper functions.

You may have read that you have to think aloud when you write a program. If it works for you, great; follow that. For some people, like me, I usually get lost in thoughts if I do that. So, what I did was tell the interviewer I will take 5 minutes to analyze the problem, come up with a solution, and then explain it step by step. If you get stuck, don't just stare at the board; tell the interviewer your logic and where you are getting stuck, as they may give you helpful hints.

The first round is usually easy; they want you to get comfortable. So, don't ignore programs like Fibonacci or common factor, which are very basic problems. As the rounds progress, it becomes harder. Your energy levels and thinking speed drop as you cruise through the day. Make sure you have practiced working on problems for a long period. For this, just like a week before, try to set up mock interviews with your friends, stretched out for a day, packed with five 45-minute interviews with 15-minute breaks. Or, if your friends are busy, ask them to randomly pick problems, write them on pieces of paper, and place them into 5 different files. Try to work on them the whole day. Trust me, this will definitely help you. On the day before the interview, please relax and get a lot of sleep. Don't try to read something you don't know, because it messes up things you do know and drops your confidence levels.

Focus on string manipulation, lists, and tree traversals. These are very, very important topics for a Microsoft interview. Learn from the mistakes other people made; trust me, it will make you a better programmer. Good luck, fellow programmers!

Test a function that converts a string to an integer. The string here can be of any length.